If you noticed an Internet speed drop after upgrading to the latest version of Windows 10, the following troubleshooting guide may help resolve it. It may be particularly useful if the Internet speed was fine on previous versions of Windows, and is no longer after the upgrade to Windows 10 Anniversary Update edition . Microsoft introduced a feature called Window Auto-Tuning back in Windows Vista, and has made it part of any newer version of Windows as well. Set to on by default, it is designed to improve performance for programs that receive TCP data over a network. While data transfers should be more efficient as a general rule, users may experience slower than usual data transfer speeds under certain conditions or even connectivity issues. Managing Window Auto-Tuning in Windows 10 The first thing you may want to do is check the status of Window Auto-Tuning. If it is turned off for instance, it is likely that it is not the case for the slow downs, but if it is set, it may very